Why learn to play an instrument?
It's not too late to learn! Research has shown that adults who take up learning a musical instrument in adulthood gain benefits by learning. It has been proven that those who receive instrumental lessons showed significant gains in memory and verbal fluency. They also improved the speed of processing information and their ability to plan improved. The adult brain has the capacity to take on this leaning skill and in doing so it preserves, and builds cognitive skills.
The beneficial impact of learning an instrument as an adult is great but primarily it'll bring enjoyment and a sense of self satisfaction.